Titanium oxygen cluster modified TiO2 catalyst with high catalysis and easy recovery as well as preparation method and application of titanium oxygen cluster modified TiO2 catalyst

Abstract

The invention provides a high-catalysis and easy-to-recover titanium oxygen cluster modified TiO2 catalyst as well as a preparation method and application thereof. According to the preparation method, TiO2 is modified through {Ti18O27} titanium oxygen clusters, atomic-scale accurate modification is realized by utilizing a unique pentagonal prism structure of the {Ti18O27} titanium oxygen clusters and interaction of sulfate radicals and water ligands on the surfaces of the {Ti18O27} titanium oxygen clusters and the surface of a TiO2 carrier, the {Ti18O27} titanium oxygen cluster modified TiO2 catalyst is successfully obtained, the specific surface area and the pore structure of the catalyst are greatly increased, the light absorption and charge separation efficiency is enhanced, and the application prospect is wide. The obvious band gap narrowing is realized, and the light response range is successfully expanded to a visible light region. Under the irradiation of visible light (lambda is greater than or equal to 400 nm), the degradation rate on a typical pollutant methyl orange can be more than 3 times of that of unmodified TiO2, and excellent visible light catalytic activity is shown.

Description

Technical Field

[0001] This invention relates to highly catalytic, easily recyclable titanium oxide cluster-modified TiO2 catalysts, their preparation methods, and applications, belonging to the fields of photocatalytic materials and fine chemical synthesis technology. Background Technology

[0002] Water pollution has become a critical issue that urgently needs to be addressed. Semiconductor heterogeneous photocatalysis, as a green and environmentally friendly technology, holds promise for directly utilizing sunlight to catalytically degrade pollutants in water, possessing many significant advantages: abundant energy sources, low cost, and environmental friendliness, thus attracting widespread attention.

[0003] For over four decades, titanium-based photocatalysts have been the most widely used and representative photocatalysts, with in-depth and extensive basic and applied research conducted in areas such as photocatalytic degradation of organic pollutants in water, water splitting for hydrogen production, and photoelectric conversion. Due to the high abundance of titanium in the Earth's crust, its oxide—titanium dioxide—is one of the most abundant compounds on Earth and is widely used in various fields including industry, food, and the environment.

[0004] Titanium dioxide (TiO2) can be extracted from ilmenite through acid decomposition or prepared from titanium tetrachloride. It has the characteristics of high dielectric constant and excellent electrical properties. TiO2 is a chemically stable n-type semiconductor material. In nature, it exists in three crystal forms: anatase, rutile, and brookite. Its band gap is relatively wide, with the anatase form at 3.2 eV and the rutile form at 3.0 eV. It can only be excited by ultraviolet light, which greatly reduces its utilization of sunlight.

[0005] The photocatalytic efficiency of a catalyst is closely related to the time it takes for excited-state electrons and holes to reach the material surface. When TiO2 particles are used as photocatalysts, the smaller the particle size, the more electrons and holes reach the reaction surface, and the higher the photocatalytic efficiency. However, due to its large band gap, TiO2 produces electron-hole pairs that recombine easily and have short lifetimes, as well as a narrow photoresponse range. This not only limits its photocatalytic activity but also restricts the available spectral range.

[0006] Therefore, the surface and structure of TiO2 need to be modified to improve its photocatalytic efficiency and utilization of sunlight.

[0007] TiO2-catalyzed degradation of organic pollutants is a complex chemical process, and catalyst activity is influenced by numerous factors. With advancements in catalytic chemistry and photochemistry, it has been found that catalysts with larger specific surface areas, superior adsorption properties, and higher visible light utilization efficiency generally exhibit better catalytic performance. Therefore, methods such as doping, surface modification, construction of heterojunction structures, and dye-sensitized visible light induction have been proposed to improve the activity of TiO2 catalysts. However, limitations such as complex and expensive processes, low light energy utilization, and low catalyst recovery rates have hindered the widespread industrial application of TiO2-catalyzed degradation of organic pollutants. Therefore, the preparation of a simple, highly efficient, and easily recoverable TiO2 catalyst has remained a research hotspot and a key objective in this field. Summary of the Invention

[0008] To address the shortcomings of existing technologies, this invention provides a highly catalytic, easily recyclable titanium oxide cluster-modified TiO2 catalyst, its preparation method, and its applications, overcoming various problems existing in the prior art.

[0009] To achieve the above or other objectives, the present invention is implemented through the following technical solutions.

[0010] The first objective of this invention is to provide a method for preparing a highly catalytic and easily recyclable titanium oxide cluster modified TiO2 catalyst.

[0011] A method for preparing a highly catalytic and easily recoverable titanium oxide cluster-modified TiO2 catalyst includes the following steps: 1) Take titanium dioxide support, add solvent and titanium oxide cluster, stir, then centrifuge, wash and dry to obtain the precursor; 2) The precursor was calcined, cooled to room temperature after calcination, washed, centrifuged and dried to obtain the titanium oxide cluster modified TiO2 catalyst.

[0012] According to a preferred embodiment of the present invention, in step 1), the phase structure of the titanium dioxide support is selected from one or more of anatase, rutile, P25, and TiO2 nanosheets.

[0013] According to a preferred embodiment of the present invention, in step 1), the titanium oxide cluster is {Ti 18 O 27 Titanium oxide clusters.

[0014] According to a preferred embodiment of the present invention, in step 1), the mass ratio of titanium dioxide support to titanium oxide cluster is 1:(1~10).

[0015] More preferably, in step 1), the mass ratio of titanium dioxide support to titanium oxide cluster is 1:(1~6).

[0016] Most preferably, in step 1), the mass ratio of titanium dioxide support to titanium oxide cluster is 1:5.4.

[0017] According to a preferred embodiment of the present invention, in step 1), the solvent is selected from one of acetonitrile, methanol, ethanol, acetone, and tetrahydrofuran.

[0018] According to a preferred embodiment of the present invention, in step 1), the mass-to-volume ratio of the titanium dioxide carrier to the solvent is 1:(10~50), unit: g / mL.

[0019] More preferably, in step 1), the mass-to-volume ratio of titanium dioxide carrier to solvent is 1:(20~30), unit: g / mL.

[0020] According to a preferred embodiment of the present invention, in step 1), the stirring time is 6 to 24 hours.

[0021] According to a preferred embodiment of the present invention, in step 1), ether is used for washing.

[0022] According to a preferred embodiment of the present invention, in step 1), the drying temperature is 50~100 ℃ and the drying time is 2 h~24 h.

[0023] According to a preferred embodiment of the present invention, in step 2), the calcination temperature is 300~500 ℃ and the calcination time is 1~4 h.

[0024] In a further preferred embodiment, in step 2), the calcination temperature is 400~500 ℃ and the calcination time is 1~3 h.

[0025] According to a preferred embodiment of the present invention, in step 2), the drying temperature is 50~100℃ and the drying time is 2 h~24 h.

[0026] The second objective of this invention is to provide a highly catalytic and easily recyclable titanium oxide cluster-modified TiO2 catalyst.

[0027] A highly catalytic and easily recyclable titanium oxide cluster-modified TiO2 catalyst was prepared using the above method, with a particle size of 7.1~24.2 nm.

[0028] This invention uses {Ti 18 O 27 Titanium oxide clusters can be used to modify TiO2, allowing for precise modification of the TiO2 surface by up to 18 titanium atoms. 18 O 27 The unique pentagonal prism structure of the titanium oxide cluster, through the interaction of its surface sulfate and water ligands with the TiO2 support surface, enables atomic-level precise modification, successfully obtaining {Ti...} 18 O 27Titanium oxide clusters modify TiO2 catalysts, which greatly increase the specific surface area and pore structure of the catalyst, and enhance the light absorption and charge separation efficiency.

[0029] The third objective of this invention is to provide applications of the above-mentioned highly catalytic and easily recyclable titanium oxide cluster-modified TiO2 catalyst.

[0030] The above-mentioned highly catalytic and easily recoverable titanium oxide cluster-modified TiO2 catalysts are used in the photodegradation of pollutants.

[0031] According to a preferred embodiment of the present invention, the specific application method is as follows: A TiO2 catalyst modified with titanium oxide clusters was added to a pollutant and reacted under light conditions. After the reaction was completed, the catalyst was recovered and recycled.

[0032] According to a preferred embodiment of the present invention, the contaminant is selected from one or more of methyl orange solution, methylene blue solution, and p-chlorophenol.

[0033] According to a preferred embodiment of the present invention, the photoreaction time is 1 h to 4 h and the phototemperature is 23°C to 27°C.

[0034] According to a preferred embodiment of the present invention, the illumination conditions are: λ ≥ 400 nm, light intensity 130-140 mW / cm². 2 Visible light.

[0035] According to a preferred embodiment of the present invention, the mass ratio of the titanium oxide cluster-modified TiO2 catalyst to the pollutant is 10:1 to 100:1.

[0036] Technical features and advantages of the present invention: 1. This invention uses {Ti} 18 O 27 Titanium oxide clusters can be used to modify TiO2, allowing for precise modification of the TiO2 surface by up to 18 titanium atoms. 18 O 27 The unique pentagonal prism structure of the titanium oxide cluster, through the interaction of its surface sulfate and water ligands with the TiO2 support surface, enables atomic-level precise modification, successfully obtaining {Ti...} 18 O 27 Titanium oxide clusters modify TiO2 catalysts, which greatly increase the specific surface area and pore structure of the catalyst, and enhance the light absorption and charge separation efficiency.

[0037] 2. Significantly improved visible light photocatalytic efficiency: This invention utilizes {Ti} 18 O 27Modifying TiO2 with titanium oxide clusters significantly narrowed the bandgap (e.g., the direct bandgap in Example 1 was 2.60 eV, Table 1), successfully extending its photoresponse range into the visible light region. Under visible light (λ ≥ 400 nm) irradiation, the degradation rate of the typical pollutant methyl orange was more than three times that of unmodified TiO2 (Application Example 1 and...). Figure 3 It exhibits excellent visible light photocatalytic activity.

[0038] 3. Possesses broad-spectrum pollutant degradation capabilities: The catalyst of this invention is not only effective for model dye molecules, but also exhibits excellent removal efficiency for structurally stable and recalcitrant organic pollutants such as p-chlorophenol (Application Example 2), demonstrating the universality of its catalytic active center and its broad application potential in the treatment of complex water bodies in practice. Attached Figure Description

[0039] Figure 1 The {Ti} prepared in Example 1 18 O 27 TEM image of anatase catalyst modified with titanium oxide clusters at low magnification (scale bar 500 nm).

[0040] Figure 2 The {Ti} prepared in Example 1 18 O 27 TEM image of anatase catalyst modified with titanium oxide clusters at high magnification (scale bar 200 nm).

[0041] Figure 3 For example 1, {Ti} 18 O 27 Degradation curves of methyl orange obtained by modifying anatase catalyst with titanium oxide clusters and anatase under visible light.

[0042] Figure 4 The degradation curves of methyl orange under visible light are shown in Application Examples 1, 3 to 8.

[0043] Figure 5 The degradation curves of methyl orange under visible light are shown in Application Examples 1, 9, and 10.

[0044] Figure 6 The degradation curve of methyl orange under visible light is shown in Application Example 2.

[0045] Figure 7 The degradation curves of methyl orange under visible light are shown in Application Examples 11-13.

[0046] Figure 8 The degradation curve of p-chlorophenol under visible light is shown in Application Example 14. Detailed Implementation

[0047] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, unless otherwise specified, the following embodiments and features can be combined with each other. It should also be understood that the terminology used in the embodiments of the present invention is for describing specific implementation schemes and not for limiting the scope of protection of the present invention. Test methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions or according to the conditions recommended by the respective manufacturers.

[0048] It should be noted that the terms such as "upper", "lower", "left", "right", "middle" and "one" used in this specification are only for clarity of description and are not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered as part of the scope of the invention.

[0049] The technical solution of the present invention will be described in detail below through several specific embodiments and comparative examples. Unless otherwise stated, the raw materials and reagents used in the following embodiments are commercially available products, or can be prepared by conventional methods in the art. Unless otherwise specified, the detection methods used in the embodiments of the present invention are conventional detection methods in the industry.

[0050] {Ti 18 O 27 Titanium oxide clusters were prepared according to the reference J. Am. Chem. Soc. 2016, 138, 11097-11100, or by the following method: 182723046 6+ That is, {Ti 18 O 27 Synthesis of Titanium Oxide Clusters Take 100 mL of 1 mol / L TiCl4 aqueous solution, add 4.26 g Li2SO4·H2O (1 / 3 mol / L) and 27.8 g (1 mol / L) tetrabutylammonium chloride (TBAC), stir at room temperature for 24 h, then transfer to a beaker and slowly evaporate the solvent at room temperature until a large amount of colorless crystals precipitate. Filter, dry, and collect the product to obtain [TiCl4]. 18 O 27 (OH2) 30 (SO4)6] 6+ , that is, {Ti 18 O 27 Titanium oxide clusters.

[0051] Anatase is obtained using the following methods: Synthesis of anatase Weigh 10 g of tetraisopropyl titanate and slowly add it dropwise to 100 mL of water while stirring vigorously. After the addition is complete, place the mixture in a reaction vessel and hydrothermally react at 180 °C for 24 h. After the reaction is complete, cool to room temperature, centrifuge, wash three times with water, and dry at 100 °C to obtain powdered anatase.

[0052] Preparation of rutile: Weigh 4 g of anatase and calcine it in a muffle furnace at 600°C for 10 h to obtain powdered rutile.

[0053] Example 1 {Ti 18 O 27 The preparation method of titanium oxide cluster-modified anatase includes the following steps: 1) Weigh 0.1 g of anatase and place it in a 5 mL serum bottle, add 2 mL of acetonitrile and 0.54 g of Ti 18 O 27 Stir for 12 h, centrifuge for 10 min, discard the supernatant, wash with ether and dry to obtain a solid.

[0054] 2) The solid was transferred to an evaporating dish and calcined in a muffle furnace at 400°C for 2 h. After cooling to room temperature, it was washed with water and centrifuged three times. The resulting solid was dried in an oven at 100°C for 3 h to obtain {Ti}. 18 O 27 {Ti} with a mass ratio of 5.4:1 to anatase 18 O 27 Titanium oxide cluster modified catalyst.

[0055] Take {Ti 18 O 27 Titanium oxide cluster-modified anatase powder was characterized by TEM, such as... Figure 1 , Figure 2 As shown, the obtained material has relatively uniform particle size, and the particles exhibit a nanoscale morphology with an average particle size of 7.5 nm.

[0056] Example 2 The preparation method is the same as that described in Example 1, except that the sample is calcined at 300°C for 2 hours in a muffle furnace.

[0057] Example 3 The preparation method is the same as that described in Example 1, except that the sample is calcined at 350°C for 2 hours in a muffle furnace.

[0058] Example 4 The preparation method is the same as that described in Example 1, except that the sample is calcined at 450°C for 2 hours in a muffle furnace.

[0059] Example 5 The preparation method is the same as that described in Example 1, except that the sample is calcined at 500°C for 2 hours in a muffle furnace.

[0060] Example 6 The preparation method is the same as that described in Example 1, except that: Add 0.1 g anatase and 0.18 g Ti 18 O 27}, that is, we get {Ti 18 O 27} modified anatase catalyst (anatase and {Ti 18 O 27 The mass ratio of titanium oxide clusters is 1.8:1.

[0061] Example 7 The preparation method is the same as that described in Example 1, except that: Add 0.1 g anatase and 0.9 g Ti 18 O 27}, that is, we get {Ti 18 O 27} modified anatase catalyst (anatase and {Ti 18 O 27 (The mass ratio of titanium oxide clusters is 9:1).

[0062] Example 8 The preparation method is the same as that described in Example 1, except that: Add 0.1 g P25 and 0.18 g Ti 18 O 27}, that is, we get {Ti 18 O 27 P25 catalyst modified with}

[0063] Example 9 The preparation method is the same as that described in Example 1, except that: Add 0.1 g P25 and 0.54 g Ti. 18 O 27}, that is, we get {Ti 18 O 27 P25 catalyst modified with}

[0064] Example 10 The preparation method is the same as that described in Example 1, except that: Add 0.1 g P25 and 0.9 g Ti.18 O 27}, that is, we get {Ti 18 O 27 P25 catalyst modified with}

[0065] Example 11 The preparation method is the same as that described in Example 1, except that: Add 0.1 g rutile and 0.54 g Ti 18 O 27}, that is, we get {Ti 18 O 27 Modifying rutile catalysts.

[0066] Example 12 The preparation method is the same as described in Example 1, except that 0.1 g of nanosheets and 0.54 g of {Ti} are added. 18 O 27}, that is, we get {Ti 18 O 27 Modified nanosheet catalysts.

[0067] Comparative Example 1 The preparation method is the same as that described in Example 1, except that the sample is calcined at 550°C for 2 hours in a muffle furnace.

[0068] Comparative Example 2 The preparation method is the same as that described in Example 1, except that the sample is calcined at 600°C for 2 hours in a muffle furnace.

[0069] Performance Characterization The titanium dioxide catalysts modified by different titanium oxide clusters prepared in Examples 1 to 14, including anatase, rutile, P25, and others, were characterized by X-ray powder diffraction (XRD), transmission electron microscopy, and ultraviolet-visible diffuse reflectance spectroscopy (UV-VisDRS). The crystal forms, crystal form ratios, particle sizes, direct band gaps, and indirect band gaps obtained by characterization are shown in Table 1.

[0070] Table 1. Crystal form, crystal form ratio, particle size, direct band gap, and indirect band gap of different products

[0071] As can be seen from Table 1, {Ti 18 O 27Titanium oxide cluster modification significantly altered the properties of the TiO2 catalyst. The modified catalyst changed color from white to brown, and its direct band gap (e.g., reduced to 2.60 eV in Example 1) was significantly narrower compared to unmodified TiO2 (3.16 eV), demonstrating a substantial enhancement in visible light absorption. Furthermore, the calcination temperature was crucial; highly active catalysts were obtained within the 300-500℃ range, while excessively high temperatures (e.g., 550-600℃ in Comparative Examples 1 and 2) led to band gap recovery, increased particle size, and ineffective modification. This modification strategy was effective on various TiO2 supports, including anatase, P25, and rutile, demonstrating its versatility.

[0072] Application Example 1 Take 10 mg of the catalyst prepared in Example 1, place it in a 25 mL serum bottle, and add 20 mL of 2×10⁻⁶ mol / L serum. -5 A mol / L methyl orange solution was stirred for 20 minutes in the dark. A 2 mL sample was taken, centrifuged, and filtered. The remaining serum sample was irradiated with a xenon lamp (using a 400 nm UV filter, wavelength ≥ 400 nm, 300 W) at a distance of 16 cm from the liquid surface. During irradiation, a 2 mL sample was taken at intervals and centrifuged and filtered. The absorption spectra of the samples taken under dark conditions and at different irradiation times were measured using a UV-Vis spectrophotometer (with a baseline calibrated three times with water). The absorbance at the maximum absorption wavelength of the colored pollutant was used as the concentration C (463 nm for methyl orange). A graph of C / C0 (C0 being the absorbance of the dark reaction sample under dark conditions) against time t was plotted to obtain the curve of methyl orange degradation by the catalyst. Simultaneously, anatase was used as a control, and the degradation curve of methyl orange by anatase was obtained following the above procedure. The degradation curves of methyl orange by anatase and catalyst in Example 1 are shown below. Figure 3 As shown, from Figure 3 As can be seen from this, around 100 minutes {Ti 18 O 27 The modified anatase has largely degraded, and the degradation time of the unmodified sample is expected to be 3-3.5 times longer. This indicates that the modified Ti... 18 This will significantly improve the degradation effect on methyl orange dyes.

[0073] Application Example 2 Take 10 mg of the catalyst prepared in Example 1, place it in a 25 mL serum bottle, and add 20 mL of 2×10⁻⁶ mol / L serum. -5A mol / L p-chlorophenol solution was stirred for 20 minutes in the dark. A 2 mL sample was taken, centrifuged, and filtered. The remaining serum sample was irradiated with a xenon lamp (using a 400 nm UV filter, wavelength ≥ 400 nm, 300 W) at a distance of 16 cm from the liquid surface. During irradiation, a 2 mL sample was taken at intervals and centrifuged and filtered. The absorption spectra of the samples taken under dark conditions and at different irradiation times were measured using a UV-Vis spectrophotometer. The concentration C was calculated based on the absorbance at the wavelength of maximum absorption of the pollutant. A graph of C / C0 (where C0 is the absorbance of the dark reaction sample under dark conditions) against time t was plotted to obtain the curve of p-chlorophenol degradation by the catalyst.

[0074] Simultaneously, anatase was used as a control, and the degradation curves of p-chlorophenol by anatase were obtained following the above procedures. The degradation curves of p-chlorophenol by the catalyst of Example 1 and anatase are shown below. Figure 6 As shown.

[0075] from Figure 6 As can be seen from this, {Ti 18 O 27 The modified anatase showed significantly better degradation efficiency for recalcitrant p-chlorophenol under visible light than the unmodified anatase, demonstrating the versatility and high efficiency of the catalyst in treating a variety of pollutants.

[0076] Application Example 3 The experimental conditions are the same as in Application Example 1, except that the {Ti} prepared in Example 2 is used in this application example. 18 O 27 Modified anatase was used as a catalyst.

[0077] Application Example 4 The experimental conditions are the same as in Application Example 1, except that the {Ti} prepared in Example 3 is used in this application example. 18 O 27 Modified anatase was used as a catalyst.

[0078] Application Example 5 The experimental conditions are the same as in Application Example 1, except that the {Ti} prepared in Example 4 is used in this application example. 18 O 27 Modified anatase was used as a catalyst.

[0079] Application Example 6 The experimental conditions are the same as in Application Example 1, except that the {Ti} prepared in Example 5 is used in this application example. 18 O 27 Modified anatase was used as a catalyst.

[0080] Application Example 7 The experimental conditions are the same as in Application Example 1, except that the {Ti} prepared in Comparative Example 1 is used in this application example. 18 O 27 Modified anatase was used as a catalyst.

[0081] Application Example 8 The experimental conditions are the same as in Application Example 1, except that the {Ti} prepared in Comparative Example 2 is used in this application example. 18 O 27 Modified anatase was used as a catalyst.

[0082] Application Example 9 The experimental conditions are the same as in Application Example 1. The difference is that in this application example, the {Ti} prepared in Example 6 is used. 18 O 27 Modified anatase was used as a catalyst.

[0083] Application Example 10 The experimental conditions are the same as in Application Example 1. The difference is that in this application example, the {Ti} prepared in Example 7 is used. 18 O 27 Modified anatase was used as a catalyst.

[0084] Application Example 11 The experimental conditions are the same as in Application Example 1. The difference is that in this application example, the {Ti} prepared in Example 8 is used. 18 O 27 The modified P25 catalyst was used as a catalyst to degrade methyl orange.

[0085] Application Example 12 The experimental conditions are the same as in Application Example 1. The difference is that in this application example, the {Ti} prepared in Example 9 is used. 18 O 27 The modified P25 catalyst was used as a catalyst to degrade methyl orange.

[0086] Application Example 13 The experimental conditions are the same as in Application Example 1, except that in this application example, the {Ti} prepared in Example 10 is used. 18 O 27 The modified P25 catalyst was used as a catalyst to degrade methyl orange.

[0087] The degradation curves of methyl orange by the catalysts in Examples 8-10 and P25 are shown below. Figure 7 As shown.

[0088] from Figure 7 As can be seen, the catalysts of Examples 8-10 exhibit significant degradation efficiency for recalcitrant methyl orange under visible light.

[0089] Application Example 14 {Ti} prepared using Example 9 18 O 27 The modified P25 catalyst (titanium oxide cluster to P25 mass ratio of 5.4:1) was used as a catalyst to degrade p-chlorophenol. The degradation curve of p-chlorophenol by this catalyst is shown in the figure below. Figure 8 As shown.

[0090] Experimental Example The curves obtained during the degradation process of Application Examples 1, 3 to 8 are shown below. Figure 4 As shown, from Figure 4 It can be seen that under visible light, the catalysts prepared by calcination at 300 ℃ and 350 ℃ have similar catalytic degradation effects on methyl orange, with the 300 ℃ catalyst showing a slight advantage. Both catalysts exhibit very rapid degradation rates, completing degradation within 40 minutes. In contrast, the degradation rates of catalysts prepared by calcination at 400 ℃, 450 ℃, and 500 ℃ decrease sequentially, but their advantages over anatase are still evident. The 400 ℃ calcination catalyst completes degradation in approximately 100 minutes, showing a relatively fast degradation rate; the 450 ℃ and 500 ℃ catalysts complete degradation in approximately 140-180 minutes. When the calcination temperature rises to 550 ℃, the degradation rate decreases significantly, with less than 40% of methyl orange degraded after 160 minutes. At 600 ℃, the degradation rate further decreases, with less than 20% of methyl orange degraded after 160 minutes. This may be because the rutile phase gradually increases with increasing calcination temperature, slowing down the degradation rate. Therefore, the degradation rate of {Ti} varies with calcination temperature. 18 O 27 The modified anatase exhibits different catalytic degradation effects on methyl orange under visible light.

[0091] The curves obtained during the degradation process of Application Example 1, Application Example 9, and Application Example 10 are shown below. Figure 5 As shown, from Figure 5 It can be seen from the anatase-modified titanium oxide cluster {Ti 18 O 27 The loading of methyl orange significantly affects catalytic performance. When the loading is increased from low (mass ratio 1.8:1, application example 9) to medium (mass ratio 5.4:1, application example 1), the degradation rate of methyl orange is significantly improved; while when the loading is further increased to high (mass ratio 9:1, application example 10), the degradation performance is comparable to that of the medium loading level, indicating that there is an optimized loading plateau within this range.

[0092] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A method for preparing a highly catalytic and easily recoverable titanium oxide cluster-modified TiO2 catalyst, comprising the following steps: 1) Take titanium dioxide support, add solvent and titanium oxide cluster, stir, then centrifuge, wash and dry to obtain the precursor; 2) The precursor was calcined, cooled to room temperature after calcination, washed, centrifuged and dried to obtain the titanium oxide cluster modified TiO2 catalyst.

2. The preparation method according to claim 1, characterized in that, In step 1), the phase structure of the titanium dioxide support is selected from one or more of anatase, rutile, P25, and TiO2 nanosheets.

3. The preparation method according to claim 1, characterized in that, In step 1), the titanium oxide cluster is {Ti 18 O 27 Titanium oxide clusters.

4. The preparation method according to claim 1, characterized in that, In step 1), the mass ratio of titanium dioxide support to titanium oxide cluster is 1:(1 ~ 10).

5. The preparation method according to claim 1, characterized in that, In step 1), the solvent is selected from one of acetonitrile, methanol, ethanol, acetone, and tetrahydrofuran.

6. The preparation method according to claim 1, characterized in that, In step 1), the mass-to-volume ratio of titanium dioxide carrier to solvent is 1:(10~50), unit: g / mL.

7. The preparation method according to claim 1, characterized in that, In step 1), the stirring time is 6~24 h, the washing is done with ether, the drying temperature is 50~100 ℃, and the drying time is 2 h~24 h.

8. The preparation method according to claim 1, characterized in that, In step 2), the calcination temperature is 300~500 ℃, the calcination time is 1~4 h, the drying temperature is 50~100 ℃, and the drying time is 2 h~24 h.

9. A highly catalytic and easily recoverable titanium oxide cluster-modified TiO2 catalyst, prepared by any one of the methods of claims 1-8, having a particle size of 7.1~24.2 nm.

10. The application of the highly catalytic and easily recyclable titanium oxide cluster-modified TiO2 catalyst according to claim 9 in the photodegradation of pollutants, specifically the following application method: A TiO2 catalyst modified with titanium oxide clusters was added to a pollutant, and the reaction was carried out under light irradiation. After the reaction was completed, the catalyst was recovered and recycled. The contaminants are selected from one or more of methyl orange solution, methylene blue solution, and p-chlorophenol. The photoreaction time was 1 h to 4 h, the phototemperature was 23℃ to 27℃, and the photoconditions were: λ ≥ 400 nm and light intensity 130-140 mW / cm². 2 The visible light intensity was measured, and the mass ratio of the titanium oxide cluster-modified TiO2 catalyst to the pollutants was 10:1 to 100:1.

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